補(bu)(bu)償(chang)(chang)(chang)器(qi)習慣上(shang)(shang)(shang)也(ye)叫膨脹節，或伸(shen)縮節。由構成其(qi)(qi)工(gong)(gong)作主體(ti)的波紋管(guan)(guan)(guan)(guan)（一(yi)(yi)種彈(dan)性(xing)元(yuan)件）和端管(guan)(guan)(guan)(guan)、支(zhi)架、法(fa)蘭(lan)、導(dao)管(guan)(guan)(guan)(guan)等(deng)附件組成。 屬于一(yi)(yi)種補(bu)(bu)償(chang)(chang)(chang)元(yuan)件。利用其(qi)(qi)工(gong)(gong)作主體(ti)波紋管(guan)(guan)(guan)(guan)的有(you)效伸(shen)縮變(bian)形，以吸收(shou)管(guan)(guan)(guan)(guan)線(xian)、導(dao)管(guan)(guan)(guan)(guan)、容器(qi)等(deng)由熱(re)脹冷縮等(deng)原因而產生的尺寸(cun)變(bian)化，或補(bu)(bu)償(chang)(chang)(chang)管(guan)(guan)(guan)(guan)線(xian)、導(dao)管(guan)(guan)(guan)(guan)、容器(qi)等(deng)的軸向(xiang)(xiang)、橫向(xiang)(xiang)和角向(xiang)(xiang)位移。也(ye)可用于降噪(zao)減(jian)振。在現代工(gong)(gong)業中用途廣泛。供熱(re)上(shang)(shang)(shang)，為了防止供熱(re)管(guan)(guan)(guan)(guan)道升溫時，由于熱(re)伸(shen)長或溫度應力而引(yin)起管(guan)(guan)(guan)(guan)道變(bian)形或破壞，需要在管(guan)(guan)(guan)(guan)道上(shang)(shang)(shang)設置補(bu)(bu)償(chang)(chang)(chang)器(qi)，以補(bu)(bu)償(chang)(chang)(chang)管(guan)(guan)(guan)(guan)道的熱(re)伸(shen)長，從而減(jian)小管(guan)(guan)(guan)(guan)壁的應力和作用在閥件或支(zhi)架結構上(shang)(shang)(shang)的作用力。